Arrangement for maintaining a shiftable member in a plurality of shifted positions

ABSTRACT

A housing member has an interior passage and a slide member is located in this passage and shiftable axially of the same between an arrest and at least one further position. An assembly is also located in this passage and includes a slidable control member which contacts the slide member and a biasing spring which biases the control member into such contact. A first recess is formed in one of the members and an arresting element of circular crosssection is received in this first recess and in part projects from the same. A second recess is formed in the control member and adapted to have the element snap into and out of it. The second recess is at least in part bounded by a flanking surface having a first portion which engages the arresting element when the slide member is in the rest position thereof, and which first portion includes a first angle with the longitudinal axis of the passage. The flanking surface further has a second portion which engages the arresting element when the slide member is in its further position, and this second portion includes with the longitudinal axis a larger second angle.

United States Patent Schwerin June 24, 1975 SHIFTED POSITIONS Primary Examiner-Charles J. Myhre Assistant E.\-aminerlra S. Lazarus Attorney Agent or FirmMichael S. Striker [75] Inventor: Giinther Schwerin, Moglingen,

Germany 57 ABSTRACT [73] Assigneei Robert Bosch Stuttgart. A housing member has an interior passage and a slide Germany member is located in this passage and shiftable axially [721 Filed: Oct 17 1973 of the same between an arrest and at least one further position. An assembly is also located in this passage [21 1 Appl. No.: 407,256 and includes a slidable control member which contacts the slide member and a biasing spring which biases the control member into such contact. A first I30] Forelgn fpphcauon Priority Data T) 7 recess is formed in one of the members and an arrest- 1 Germany 55:70 ing element of circular cross-section is received in this first recess and in part projects from the same. A sec- 251/297; 74/527 ond recess is formed in the control member and adapted to have the element snap mm and out of it. l58l Fleld of Search 251/297 i g% The second recess is at least in part bounded by a flanking surface having a first portion which engages the arresting element when the slide member is in the lsfil References rest position thereof, and which first portion includes UNlTED STATES PATENTS a first angle with the longitudinal axis of the passage. 3,088.48) 5/l963 Stacey 251/297 X The flanking surface further has a second portion 3l28. 4/l964 nnis 137/62427 X which engages the arresting element when the slide 3 1 W965 f l ct uh 25l/297 X member is in its further position, and this second pori2 tion includes with the longitudinal axis a larger second ,e arncs C 21. 3,602.245 8/1971 Mcisel 25l/297 X angle 3.618634 1 H197! Nelson l37/624.27 8 Claims, 5 Drawing Figures A15 M g I I g I I, r eeae I 1 25 e i g 13 f M 'a i I. F l |\\Q l 22 's .e\ O ww/lwamm'l/lr/A 1 ARRANGEMENT FOR MAINTAINING A SIIIFTABLE MEMBER IN A PLURALITY OF SHIFTED POSITIONS BACKGROUND OF THE INVENTION The present invention relates generally to an arrangement for maintaining a slidable member in different positions thereof. More particularly. the invention relates to such an arrangement which is especially suitable for maintaining the slidable valve member of a slide valve in such different positions.

Arrangements of this general type are already known, for cooperation with the slidable valve member of a slide valve. Such arrangements utilize a single spring for the arresting and restoring function which they perform for the slidable valve member, and because of the utilization of a single spring, and their general arrangement they provide a considerable reliability in terms of maintaining the slidable valve member in the various positions thereof. Moreover, these constructions are relatively uncomplicated. They utilize a member which is spring-biased and provided with an annular groove of triangular cross-section. The groove is bounded by a flanking surface, that is by one side surface, which is inclined to the longitudinal axis of the slidable valve member at an angle which is coordinated with a similar angle of a flanking surface which in part bounds a recess in a housing accommodating these members. One or more spherical members are accommodated in this recess and when the valve member is to be returned from its rest position into another position, i.e., a neutral position, a force exerted by the spherical members against the housing produces a friction which counteracts the biasing forcerof the spring. This friction, however is undesirable. However, heretofore, it has been impossible to meet both requirements which should ideally be made of such an arrangement, namely to assure on the one hand that it would reliably retain the slidable member, for instance a slidable valve member, in the respective positions thereof, while on the other hand, producing the lowest possible friction. Attempts to change the angle of the respective flanks mentioned above, have not been successful, because the aforementioned two requirements are diametrally opposite.

SUMMARY OF THE INVENTION Accordingly, it is a general object of the present invention to provide an improved arrangement of the character described above, which avoids the disadvantages of the prior art.

More particularly, it is an object of the present invention to provide such an improved arrangement which not only affords reliable retention of the respective slidable member in the various positions thereof, but also assures that the lowest possible friction is developed in the arrangement when the same is utilized for permitting the slidable member to move between its various positions.

An additional object of the invention is to provide such an improved arrangement which is simple in its construction.

In keeping with these objects, and others which will become apparent hereafter, one feature of the inven tion resides, in an arrangement of the character described herein. in a combination which comprises a housing member having an interior passage and a slide member which is located in this passage and shiftable axially of the latter between a first and at least one further position. An assembly is also located in this passage and includes a slidable control member contacting the slide member, and a biasing spring biasing the control member into such contact. A first recess is formed in one of the members, and an arresting element of circular cross section is received in this first recess and in part projects from the same. A second recess is formed in the control member and adapted to have the element snap in and out of it. This second recess is at leastin part bounded by a flanking surface having a first portion which engages the arresting element when the slide member is in the first position, and which includes a first angle with the longitudinal axis of the passage. F urther, the flanking surface has a second portion which engages the arresting element when. the slide member is in the further position and which includes with the longitudinal axis a larger, second angle.

This construction assures that the portion-of the flanking surface which cooperates with the arresting member when the slide member is in the firstposition thereof, can be so constructed that on the one hand, the desired reliability of retention in the first position is achieved, whereas on the other hand, that portion of the flanking surface which cooperates with the arresting member when the slide member is in its one or more further positions, is so selected that minimum friction will develop, so that the spring can rapidly restore the slide member to its initial position. This advantage is due to the fact that in the arresting and nonarresting positions, the arresting member assumes different positions in its recess, so that a single flanking surface can be provided with two portions ,as mentioned above, which include different angles with the longitudinal axis of the passage and the slide member.

It is particularly advantageous if the two portions of the flanking surface are straight, so that problems which might arise from tolerance variations during the manufacture of the various components can be more reliably overcome. V

The novel features which are-considered as characteristic for the invention are-set forth ,in particular in the appended claims. The invention itself, however, both as to its construction and itsmethod of operation, together with additional objects and advantages thereof, will bebest understood from the following description of specific embodiments when read in .con: nection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a longitudinal section through one embodiment of theinvention;

FIG. 2 is an enlarged fragmentary sectional detail view, showing a detail of FIG. I; FIG. 3 is a view similar'to FIG. 2 but illustrating the same detail of a prior'art arrangement;

FIG. 4 is an axial section through a further embodiment of the invention; and

FIG. 5 is an axial section through still an additional I embodiment of the invention. A

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring firstly to the embodiment which is.illustrated in FIGS. 1 and 2, it will be seen that reference numeral 10 identifies an only diagrammatically illusticulated to a lever 16 which is pivoted to an arm. of'

longitudinal axis of the 'valve'member 13, one. end of which extends into the bore 23. The member 21 is further provided with an annular circumferential groove 24' of triangular cross section. That end of the member 13 which is adjacent the portion 18 is provided. with a blind bore 25 from which a plurality of radial bores 26 extend outwardly, each'of theseiaccommodating an arresting 'element'27 in form of a ball. .The diameter of the ball27 is so selected that it can slide in the radial bore 26 with a'slight pIay.-- I

A bolt 28 is guided in the bore 25 with slight'axial play as long as the memberi13 is not 'inits arrested or "rest position. The, circumference of the bolt 28 is provided with a circumferential annular groove 29 which, as shown more clearly in FIG. '2, is bonded in part by a flan'king surface3l. The surface 31 hasa first portion 32 and-an adjacent second portion 33. In accordance with the'present invention, the first portion 32 includes with the longitudinal axis of the member 13 a first angle 34, whereas :the second portion 33 includes with the same axis a second. but larger angle 35. The angle which is included by an associated cooperating flanking surface of the groove 24 with the same longitudinal "axis of'the memberl3, is also larger than the first angle 34.

The bolt 28 is provided at its end facing away from the housing ll with the shoulder 36 w hich is engaged by a'plate37.'A further plate 38 engages a retaining ring 41 atthe reduced-diameter free endof the bolt '28,-

and intermediate theplates 37 and 38 the "bolt is surrounded by a helical expansion spring 39. The bolt'is connected with the member 13 through theballs 27- which are accommodated in the bores or recesses 26 and extend into the groove 29, having limited playintermediate the closely adjacent end positions of the member13,

When the member 13' is in neutral position, which is shown in FIGS. 1 and 2, it is connected with the bolt 28 via the balls 27 and is fixed in its position with reference to the .housing 11 by the spring 39 which bears upon the plates 37 and 38.-In this position, the com- I pression of the spring doesnot act upon the member 13 and the portion 33 of the flanking surface 31 engages the balls 27.

If, now, the member 13 is moved towards the right.

in FIGS. 1 and 2, then. the increasing distance through which the member 13 travels towards the right results in an increase of the force which acts from the spring 39 (which is being compressed) via the plates 37, and the bolt 28 upon the balls 27 and thereby upon the member 13. During such movement, the portion 33 of the flanking surface 31 pushes the balls 27 outwardly towards the bore, 23. Once the member 13 reaches the 4 desired rest. position, the balls 27 travel outwardly under the biasing force of thespringinto the groove 24, forming a connection between bolt 28 and housing 1.

i In the arrested. or rest position, the balls 27 are located in such a manner that they engagethe flanking surface 31 only at the portion 32 thereof.

FIG. 2 shows that a force P which is exerted by the spring 39 upon the bolt 28 (disregarding for this purpose the frictional forces) will act upon the balls 27 with the force components P P and P The force component P, which is responsible for the frictional forces amounts in FIG. 1 to 35% of the force P. Comparing this with the prior-art embodimentwhich is illustrated in FIG-3, it will be seen that in this prior-art embodiment a corresponding force component P, equals of the force P, because the flanking surface 42 cannot be inclined more beyond what is shown in FIG. 3 for reasons of reliable engagement with the ball 27, and is straight. Thiscomparison therefore shows that by resorting to the present invention the friction during movement of the member 13 in the positions thereof can be substantially reduced, without having to sacrifice reliability in terms of the retention of the member 13 in the positions. This, means that the restoration of the member 13 from a rest position into its neutral position can-take place more. easily and more rapidly, or that the spring 39 can be made weaker, as may be deis the same as'in the embodiment of FIGS. 1 and 2 and like elements are-identifiedwithlike reference numerals.

FIG. 5 finally shows still another embodiment of the invention; this embodiment is of. the single-acting type as'oppo's'ed' to the embodiment in FIG. 4 which is of the double-acting type. The arrangement in FIG. 5 is designated in toto-with reference numeral 60 and utilizes a spring-biased member 62 which is biased by a spring 61 and acts upon balls 63, which are guided in a stationary member 64 and cooperate with the slide member 65 corresponding to the member 13 in FIG. 1. The operation is the same in'FIGS. 1 and 2, especially with respect to the flanking surfaces.

It will be appreciated that the invention is not limited to a single acting or double-acting construction and that the flanking surface-could also be provided with a curved shape for the portions 32 and 33, instead of the illustratedstraight shape. It is also possible to use cylindrical rolls instead of the illustrated balls. The groove 29can be readily and inexpensively produced by conventional material-removing techniques.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention L has been illustrated and ,described as embodied in an arrangement for-maintaining a shiftable member in a plurality of shifted positions. it

n is no'tintended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so'fully reveal the gist of the present invention that others can, by applying current knowledge. readily adapt it for various applications without omitting features that from the standpoint of prior art fairly constitute essential characteristics of the generic or specific features of this invention and therefore, such adaptations should and are intended to be comprehended Within the meaning,

and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth'in the appended claims.

I claim:

I. In an arrangement of the character described, a combination comprising a housing bounding an interior passage having a longitudinal axis; a first member coaxially accommodated in said passage and having an axially extending first sliding surface and an annular free end portion provided with at least one radially extending through hole; a second member coaxially accommodated in said passage and having an axially extending second sliding surface contacting said first sliding surface and provided with at least one arresting recess, one of said first and second members being stationary with respect to said housing and the other being mounted for movement with respect to said one member so that said sliding surfaces slide on one another; at least one arresting element of circular cross section received in said radial through hole and displaceable therein and having a diameter exceeding the length of the latter; means for moving said other member between at least one arresting position in which said through hole faces said arresting recess and said arresting element is partially received in the latter, and a rest position in which said through hole faces said second sliding surface and said arresting element bears against the same; a third member coaxially accommodated in said passage so as to have a limited degree of movement relative to said first member proportionate to the displacement of said arresting element, and having at least one flanking surface abutting against said arresting element and having a first surface portion closer to said first member and enclosing with said longitudinal axis a first acute angle, and a second surface portion farther away from said first member and enclosing with said longitudinal axis a second acute angle larger than said first acute angle; and means for biasing said third member toward said rest position with attendant abutment of said first surface portion with said arresting element when the latter is received in said arresting recess and of said second surface portion with said arresting element when the latter bears against said second sliding surface, whereby the radial forces acting between said arresting element and said second member when said second surface portion acts on the former are significantly lower than those occurring when said first surface portion acts on said arresting element so that the latter is reliably received in said arresting recess while the friction between the same and said second sliding surface is reduced.

2. A combination as defined in claim 1, wherein said arresting recess is formed in said second sliding surface, and said control recess is formed in an outer circumferential surface of said third member.

3. A combination as defined in claim 1, wherein said first. second and third members together define an annular space into which said arresting element projects out of said arresting recess. 7

4. A combination as defined in claim 1, wherein said first and second surface portions are straight in axial said first memberhas a free end located in said passage, and

said third member abuts said free end.* g

7. In a control arrangement, a combination comprising a housing bounding an interior passage having a longitudinal axis; a first membercoaxially m'ounted'in' said passage for axial movement with respect to, said housing and having an axially extending first sliding surface and an annular free end portion provided with at least one radially extending through hole; a second member rigidly connected to said housing and coaxially accommodated in said passage and having an axially extending second sliding surface contacting said first sliding surface and provided with at least one arresting recess; at least one arresting element of circular cross section received in said radial through hole and displaceable therein and having a diameter exceeding the length of the latter; means for moving said first member between at least one arresting position in which said arresting element is partially received in said arresting recess, and a rest position in which said arresting element bears against said second sliding surface; a third member coaxially accommodated in said passage so as to have a limited degree of movement relative to said first member proportionate to the displacement of said arresting element, and provided with a control recess having two flanking surfaces at least one of which abuts against said arresting element and has a first surface portion closer to said first member and enclosing with said longitudinal axis a first acute angle, and a second surface portion farther away from said first member and enclosing with said longitudinal axis a a second acute angle larger than said first acute angle; and means for biasing said third member toward said rest position with attendant abutment of said first surface portion with said arresting element when the latter is received in said arresting recess and of said second surface portion with said arresting element when the latter bears against said second sliding surface, whereby the radial forces acting between said arresting element and said second member when said second surface portion acts on the former are significantly lower than those occurring when said first surface portion acts on said arresting element so that the latter is reliably received in said arresting recess while the friction between the same and the said second sliding surface is reduced.

8. In a control arrangement, a combination comprising a housing bounding an interior passage having a longitudinal axis; a first member rigidly and coaxially attached to said housing and having an axially extending first sliding surface and an annular free end portion provided with at least one radially extending through hole; a second member mounted in said passage for coaxial movement with respect to said housing and having an axially extending second sliding surface contacting said first sliding surface and provided with an arresting recess; at least one arresting element of circular cross section received in said radial through hole and dis placeable therein and partially projecting radially outwardly therefrom; means for moving said second mem- -axially accommodated in said passage so as to have a limiteddegrce of movement relative to said first mem' ber proportionate to the displacement of said arresting element. and having a flanking surface abutting against said arresting element and having a first surface portion closer to said first member and enclosing with said longitudinal axis a first acute angle,,and a second surface portion farther, away from said first member and enclosing with said longitudinal axis a second acute angle larger than said first acute angle; and means for biasing said third member toward said rest position with attendant abutment of said first surface portion with said arresting element when the latter is received in said arresting recess and of said second surface portion with said arresting element when the latter bears against said second sliding surface. whereby the radial forces acting between said arresting element and said second memher when said second surface portion acts on the former are significantly lower than those occurring when said first surface portion acts on said arresting element so that the latter is reliably received in said arresting recess while the friction between the same and said second sliding surface is reduced. 

1. In an arrangement of the character described, a combinatioN comprising a housing bounding an interior passage having a longitudinal axis; a first member coaxially accommodated in said passage and having an axially extending first sliding surface and an annular free end portion provided with at least one radially extending through hole; a second member coaxially accommodated in said passage and having an axially extending second sliding surface contacting said first sliding surface and provided with at least one arresting recess, one of said first and second members being stationary with respect to said housing and the other being mounted for movement with respect to said one member so that said sliding surfaces slide on one another; at least one arresting element of circular cross section received in said radial through hole and displaceable therein and having a diameter exceeding the length of the latter; means for moving said other member between at least one arresting position in which said through hole faces said arresting recess and said arresting element is partially received in the latter, and a rest position in which said through hole faces said second sliding surface and said arresting element bears against the same; a third member coaxially accommodated in said passage so as to have a limited degree of movement relative to said first member proportionate to the displacement of said arresting element, and having at least one flanking surface abutting against said arresting element and having a first surface portion closer to said first member and enclosing with said longitudinal axis a first acute angle, and a second surface portion farther away from said first member and enclosing with said longitudinal axis a second acute angle larger than said first acute angle; and means for biasing said third member toward said rest position with attendant abutment of said first surface portion with said arresting element when the latter is received in said arresting recess and of said second surface portion with said arresting element when the latter bears against said second sliding surface, whereby the radial forces acting between said arresting element and said second member when said second surface portion acts on the former are significantly lower than those occurring when said first surface portion acts on said arresting element so that the latter is reliably received in said arresting recess while the friction between the same and said second sliding surface is reduced.
 2. A combination as defined in claim 1, wherein said arresting recess is formed in said second sliding surface, and said control recess is formed in an outer circumferential surface of said third member.
 3. A combination as defined in claim 1, wherein said first, second and third members together define an annular space into which said arresting element projects out of said arresting recess.
 4. A combination as defined in claim 1, wherein said first and second surface portions are straight in axial direction of said passage.
 5. A combination as defined in claim 1, wherein said first member is a valve member of a slide valve.
 6. A combination as defined in claim 2, wherein said first member has a free end located in said passage, and said third member abuts said free end.
 7. In a control arrangement, a combination comprising a housing bounding an interior passage having a longitudinal axis; a first member coaxially mounted in said passage for axial movement with respect to said housing and having an axially extending first sliding surface and an annular free end portion provided with at least one radially extending through hole; a second member rigidly connected to said housing and coaxially accommodated in said passage and having an axially extending second sliding surface contacting said first sliding surface and provided with at least one arresting recess; at least one arresting element of circular cross section received in said radial through hole and displaceable therein and having a diameter exceeding the length of the latteR; means for moving said first member between at least one arresting position in which said arresting element is partially received in said arresting recess, and a rest position in which said arresting element bears against said second sliding surface; a third member coaxially accommodated in said passage so as to have a limited degree of movement relative to said first member proportionate to the displacement of said arresting element, and provided with a control recess having two flanking surfaces at least one of which abuts against said arresting element and has a first surface portion closer to said first member and enclosing with said longitudinal axis a first acute angle, and a second surface portion farther away from said first member and enclosing with said longitudinal axis a a second acute angle larger than said first acute angle; and means for biasing said third member toward said rest position with attendant abutment of said first surface portion with said arresting element when the latter is received in said arresting recess and of said second surface portion with said arresting element when the latter bears against said second sliding surface, whereby the radial forces acting between said arresting element and said second member when said second surface portion acts on the former are significantly lower than those occurring when said first surface portion acts on said arresting element so that the latter is reliably received in said arresting recess while the friction between the same and the said second sliding surface is reduced.
 8. In a control arrangement, a combination comprising a housing bounding an interior passage having a longitudinal axis; a first member rigidly and coaxially attached to said housing and having an axially extending first sliding surface and an annular free end portion provided with at least one radially extending through hole; a second member mounted in said passage for coaxial movement with respect to said housing and having an axially extending second sliding surface contacting said first sliding surface and provided with an arresting recess; at least one arresting element of circular cross section received in said radial through hole and displaceable therein and partially projecting radially outwardly therefrom; means for moving said second member between an arresting position in which said arresting element is received in said arresting recess, and a rest position in which said arresting element bears against said second sliding surface; a third member coaxially accommodated in said passage so as to have a limited degree of movement relative to said first member proportionate to the displacement of said arresting element, and having a flanking surface abutting against said arresting element and having a first surface portion closer to said first member and enclosing with said longitudinal axis a first acute angle, and a second surface portion farther away from said first member and enclosing with said longitudinal axis a second acute angle larger than said first acute angle; and means for biasing said third member toward said rest position with attendant abutment of said first surface portion with said arresting element when the latter is received in said arresting recess and of said second surface portion with said arresting element when the latter bears against said second sliding surface, whereby the radial forces acting between said arresting element and said second member when said second surface portion acts on the former are significantly lower than those occurring when said first surface portion acts on said arresting element so that the latter is reliably received in said arresting recess while the friction between the same and said second sliding surface is reduced. 